Oestrogen and women's emotions

It's clear that oestrogen is closely linked with women's emotional wellbeing. Depression and anxiety affect women in their oestrogen-producing years more often than men or postmenopausal women. Oestrogen is also linked to mood disruptions that occur only in women - premenstrual syndrome, premenstrual dysphoric disorder and postnatal depression.

Exactly how oestrogen affects emotion is much less straightforward. Is it too much oestrogen? Not enough? It turns out oestrogen's emotional effects are nearly as mysterious as moods themselves.

Oestrogen: What's normal?

Beginning at puberty a woman's ovaries start releasing oestrogen in coordination with each monthly menstrual cycle. At mid-cycle levels suddenly spike, triggering the release of an egg (ovulation). They then fall just as quickly. During the rest of the month oestrogen levels climb and fall gradually.

Normal oestrogen levels vary widely. Large differences are typical in a woman on different days, or between two women on the same day of their cycles. The actual measured level of oestrogen doesn't predict emotional disturbances.

Hormones on the brain

That's not to say oestrogen isn't a major player in regulating moods. Oestrogen acts everywhere in the body including the parts of the brain that control emotion.

Some of oestrogen's effects include:

• Increasing serotonin, and the number of serotonin receptors in the brain
• Modifying the production and the effects of endorphins, the "feel-good" chemicals in the brain
• Protecting nerves from damage, and possibly stimulating nerve growth

What these effects mean in an individual woman is impossible to predict. Oestrogen's actions are too complex for researchers to understand fully. As an example, despite oestrogen's apparently positive effects on the brain, many women's moods improve after menopause, when oestrogen levels are very low.

Some experts believe that some women are more vulnerable to the menstrual cycle's normal changes in oestrogen. They suggest it's the roller coaster of hormones during the reproductive years that create mood disturbances.

Premenstrual syndrome (PMS) - also known as premenstrual tension (PMT)

As many as 90% of women experience unpleasant symptoms before their periods. If symptoms are reliably severe enough to interfere with life, it's defined as premenstrual syndrome (PMS). Generally speaking PMS is present when:

• Physical and emotional symptoms occur reliably a few days before multiple consecutive menses (periods)
• The symptoms go away after completing a period, and don't occur at other times
• The symptoms cause significant personal problems (such as at work, school or in relationships)
• No medicines, drugs, alcohol or other health condition might be to blame.

Bloating, swelling of arms or legs and breast tenderness are the usual physical symptoms. Feeling overly emotional, experiencing depression, anger and irritability, or having anxiety and social withdrawal may be present. As many as 20% to 40% of women may have PMS at some point in life.